Operation of buildings is a significant contributor to emissions into our atmosphere. Building operations account for a large percentage of our energy use and of our carbon-based emissions. In response to these concerns as well as rising energy costs, building designers continue to look for more energy efficient systems to facilitate building operation. Moreover, certifications such as Leadership in Energy and Environmental Design (LEED) have enticed designers and building owners to entertain alternatives to conventional building operations.
Daylighting is one aspect of this movement and involves efforts to rely on natural light to illuminate the interior of a building. Daylighting efforts may include strategically placing windows, doors, and other openings. In addition, light shelves may also be used to reflect natural light into an interior space. In most instances, light shelves may be positioned on the interior of a building at a window location. When the light shelf is positioned properly, natural sunlight is directed toward the top surface of the light shelf and reflected upward illuminating the ceiling in the interior building space. Less electrical lighting may thus be used in the spaces where light shelves are utilized and therefore the electrical lighting may be dimmed or turned off to conserve energy.
Current light shelves, however, suffer from several drawbacks. For example, current light shelves may be limited to sizes and arrangements quite closely related to glazing layouts and interior obstruction locations. In addition, known shelves often cause glare and reflect harsh light off interior hard surfaces. This does not create a very aesthetically pleasing appearance. Improvements are needed to further the use of light shelves in the building industry; such as making the design and layout more flexible, creating a more aesthetically pleasing appearance, making the use of natural light more appealing for building occupants, improving the quality of the reflected light, and facilitating ease of fabrication and installation. Improved designs can distribute light more uniformly in a room as well as distribute light greater distances.